| 摘要 |
PROBLEM TO BE SOLVED: To prevent malfunctions and failures to operate due to defects in setting a switch for setting set levels and the like, enable recognizing the defects and prevent erroneous setting, when setting is changed. SOLUTION: A protective relay is constituted of an input transformer 1, an input analog circuit 2, an A/D conversion circuit 3, an arithmetic circuit 4, a power circuit 5, a relay circuit 6, a setting completion switch 7, a setting completion switch 8, and a display circuit 9 controlled through the computing circuit 4. The state of setting switch position recognized by the computing circuit is kept displayed on the display circuit as numerical values, corresponding to each sate of switch position. When there is a change in a state of the setting switch, a numerical value corresponding the changed state of switch position is blinked on the display circuit. When the setting completion switch is turned on, the state of the setting switch is updated into the changed state of switch position, and furthermore the numerical value corresponding to the changed state of switch position, which numerical value has been blinked on the display circuit, is continuously displayed. |
